Etching compositions

ABSTRACT

The present disclosure is directed to etching compositions that are useful for, e.g., selectively removing silicon germanium (SiGe) from a semiconductor substrate as an intermediate step in a multistep semiconductor manufacturing process.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority to U.S. Provisional ApplicationSer. No. 62/811,600, filed on Feb. 28, 2019 and U.S. ProvisionalApplication Ser. No. 62/774,382, filed on Dec. 3, 2018, the contents ofwhich are hereby incorporated by reference in their entirety.

FIELD OF THE DISCLOSURE

The present disclosure relates to etching compositions and processes ofusing etching compositions. In particular, the present disclosurerelates to etching compositions that can selectively etch silicongermanium in the presence of other exposed or underlying materials, suchas metal conductors (e.g., copper), barrier materials, insulatormaterials (e.g., low-k dielectric materials).

BACKGROUND OF THE DISCLOSURE

The semiconductor industry is rapidly decreasing the dimensions andincreasing the density of electronic circuitry and electronic componentsin microelectronic devices, silicon chips, liquid crystal displays, MEMS(Micro Electro Mechanical Systems), printed wiring boards, and the like.The integrated circuits within them are being layered or stacked withconstantly decreasing thicknesses of the insulating layer between eachcircuitry layer and smaller and smaller feature sizes. As the featuresizes have shrunk, patterns have become smaller, and device performanceparameters tighter and more robust. As a result, various issues whichheretofore could be tolerated, can no longer be tolerated or have becomemore of an issue due to the smaller feature size.

In the production of advanced integrated circuits, to minimize problemsassociated with the higher density and to optimize performance, bothhigh k and low k insulators, and assorted barrier layer materials havebeen employed.

Silicon germanium (SiGe) can be utilized in the manufacturing ofsemiconductor devices, liquid crystal displays, MEMS (Micro ElectroMechanical Systems), printed wiring boards and the like, as nanowiresand/or nanosheets. For example, it can be used as a gate material in amultigate device, such as a multiple-gate field-effect transistor (FET)(e.g., a gate-all-around FET).

SUMMARY OF THE DISCLOSURE

In the construction of semiconductor devices, silicon germanium (SiGe)frequently needs to be etched. In the various types of uses and deviceenvironments of SiGe, other layers are in contact with or otherwiseexposed at the same time as this material is etched. Highly selectiveetching of the SiGe in the presence of these other materials (e.g. metalconductors, dielectric, and hard marks) is typically needed for deviceyield and long life. The etching process for the SiGe may be a plasmaetching process. However, using a plasma etching process on the SiGelayer may cause damage to either or both the gate insulating layer andthe semiconductor substrate. In addition, the etching process may removea portion of the semiconductor substrate by etching the gate insulatinglayer exposed by the gate electrode. The electrical characteristics ofthe transistor may be negatively impacted. To avoid such etching damage,additional protective device manufacturing steps may be employed, but ata significant cost.

The present disclosure relates to compositions and processes forselectively etching SiGe relative to hard mask layers, gate materials(e.g., SiN, poly-Si, or SiOx) and low-k dielectric layers (e.g., SiN,poly-Si, SiOx, carbon doped oxide, or SiCO) that are present in thesemiconductor device. More specifically, the present disclosure relatesto compositions and processes for selectively etching SiGe relative tolow-k dielectric layers.

In one aspect, the disclosure features an etching composition thatincludes a) at least one fluorine-containing acid, the at least onefluorine-containing acid including hydrofluoric acid orhexafluorosilicic acid; b) at least one oxidizing agent; c) at least oneorganic acid or an anhydride thereof, the at least one organic acidincluding formic acid, acetic acid, propionic acid, or butyric acid; d)at least one polymerized naphthalene sulfonic acid; e) at least oneamine, the at least one amine including an amine of formula (I):N—R₁R₂R₃, in which R₁ is C₁-C₈ alkyl optionally substituted by OH orNH₂, R₂ is H or C₁-C₈ alkyl optionally substituted by OH, and R₃ isC₁-C₈ alkyl optionally substituted by OH; and f) water.

In another aspect, the disclosure features a method that includescontacting a semiconductor substrate containing a SiGe film with anetching composition described herein to remove the SiGe film.

In still another aspect, the disclosure features an article formed bythe method described above, in which the article is a semiconductordevice (e.g., an integrated circuit).

DETAILED DESCRIPTION OF THE DISCLOSURE

As defined herein, unless otherwise noted, all percentages expressedshould be understood to be percentages by weight to the total weight ofthe composition. Unless otherwise noted, ambient temperature is definedto be between about 16 and about 27 degrees Celsius (° C.).

In general, the disclosure features an etching composition (e.g., anetching composition for selectively removing SiGe) that includes a) atleast one fluorine-containing acid, the at least one fluorine-containingacid including hydrofluoric acid (HF) or hexafluorosilicic acid(H₂SiF₆); b) at least one oxidizing agent, the at least one oxidizingagent including hydrogen peroxide; c) at least one organic acid, the atleast one organic acid including formic acid, acetic acid, propionicacid, or butyric acid; d) at least one polymerized naphthalene sulfonicacid; e) at least one amine, the at least one amine including an amineof formula (I): N—R₁R₂R₃, in which R₁ is C₁-C₈ alkyl optionallysubstituted by OH or NH₂, R₂ is H or C₁-C₈ alkyl optionally substitutedby OH, and R₃ is C₁-C₈ alkyl optionally substituted by OH; and f) water.

In general, the etching composition of this disclosure can include atleast one (e.g., two, three, or four) fluorine-containing agent. Thefluorine-containing acid described herein can be an inorganic acid, suchas HF or H₂SiF₆. In some embodiments, the at least onefluorine-containing acid is in an amount of at least about 0.1 wt %(e.g., at least about 0.2 wt %, at least about 0.4 wt %, at least about0.5 wt %, at least about 0.6 wt %, at least about 0.8 wt %, at leastabout 1 wt %, at least about 1.2 wt %, at least about 1.4 wt %, or atleast about 1.5 wt %) to at most about 2 wt % (e.g., at most about 1.9wt %, at most about 1.8 wt %, at most about 1.7 wt %, at most about 1.6wt %, at most about 1.5 wt %, at most about 1.2 wt %, at most about 1 wt%, or at most about 0.5 wt %) of the etching composition of thisdisclosure. Without wishing to be bound by theory, it is believed thatfluorine-containing acid can facilitate and enhance the removal of SiGeon a semiconductor substrate during the etching process.

The etching composition of this disclosure can include at least one(e.g., two, three, or four) oxidizing agent suitable for use inmicroelectronic applications. Examples of suitable oxidizing agentsinclude, but are not limited to, oxidizing acids or salts thereof (e.g.,nitric acid, permanganic acid, or potassium permanganate), peroxides(e.g., hydrogen peroxide, dialkylperoxides, urea hydrogen peroxide),persulfonic acid (e.g., hexafluoropropanepersulfonic acid,methanepersulfonic acid, trifluoromethanepersulfonic acid, orp-toluenepersulfonic acid) and salts thereof, ozone, peroxycarboxylicacids (e.g., peracetic acid) and salts thereof, perphosphoric acid andsalts thereof, persulfuric acid and salts thereof (e.g., ammoniumpersulfate or tetramethylammonium persulfate), perchloric acid and saltsthereof (e.g., ammonium perchlorate, sodium perchlorate, ortetramethylammonium perchlorate)), and periodic acid and salts thereof(e.g., periodic acid, ammonium periodate, or tetramethylammoniumperiodate). These oxidizing agents can be used singly or in combination.

In some embodiments, the at least one oxidizing agent can be from atleast about 5% by weight (e.g., at least about 6% by weight, at leastabout 7% by weight, at least about 8% by weight, at least about 9% byweight, at least about 10% by weight, at least about 11% by weight, atleast about 13% by weight, or at least about 15% by weight) to at mostabout 20% by weight (e.g., at most about 18 wt %, at most about 16 wt %,at most about 15 wt %, at most about 14 wt %, at most about 12 wt %, orat most about 10 wt %) of the etching composition of this disclosure.Without wishing to be bound by theory, it is believed that the oxidizingagent can facilitate and enhance the removal of SiGe on a semiconductorsubstrate.

In general, the etching composition of this disclosure can include atleast one (e.g., two, three, or four) organic acid or an anhydridethereof. In some embodiments, the organic acid can be formic acid,acetic acid, propionic acid, or butyric acid. In some embodiments, theorganic acid anhydride can be formic anhydride, acetic anhydride,propionic anhydride, or butyric anhydride. In some embodiments, the atleast one organic acid or an anhydride thereof can be from at leastabout 30% by weight (e.g., at least about 35% by weight, at least about40% by weight, at least about 45% by weight, at least about 50% byweight, at least about 55% by weight, or at least about 60% by weight)to at most about 90% by weight (e.g., at most about 85 wt %, at mostabout 80 wt %, at most about 75 wt %, at most about 70 wt %, at mostabout 65 wt %, at most about 60 wt %, at most about 55 wt %, at mostabout 50 wt %, at most about 45 wt %, or at most about 40 wt %) of theetching composition of this disclosure. Without wishing to be bound bytheory, it is believed that the organic acid or an anhydride thereof canfacilitate and enhance the removal of SiGe on a semiconductor substrate.

The etching composition of this disclosure can generally include atleast one polymerized naphthalene sulfonic acid (or poly(naphthalenesulfonic acid)), e.g., as a surfactant or selective inhibitor. In someembodiments, the polymerized naphthalene sulfonic acid can be a sulfonicacid having the following chemical structure:

in which n is 3, 4, 5, or 6. Commercially available examples of such thepolymerized naphthalene sulfonic acids include Takesurf A-47 seriesproducts available from Takemoto Oil & Fat Co., Ltd. In someembodiments, the at least one polymerized naphthalene sulfonic acid canbe from at least about 0.005% by weight (e.g., at least about 0.01% byweight, at least about 0.02% by weight, at least about 0.03% by weight,at least about 0.04% by weight, at least about 0.05% by weight, or atleast about 0.1% by weight) to at most about 0.15% by weight (e.g., atmost about 0.14 wt %, at most about 0.12 wt %, at most about 0.1 wt %,at most about 0.08 wt %, at most about 0.06 wt %, or at most about 0.05wt %) of the etching composition of this disclosure. Without wishing tobe bound by theory, it is believed that the polymerized naphthalenesulfonic acid can selectively inhibit the removal of SiN, poly-Si, andSiCO when SiGe is removed from a semiconductor substrate using theetching composition of this disclosure.

In general, the etching composition of this disclosure can include atleast one (e.g., two, three, or four) amine. In some embodiments, theamine can be an amine of formula (I): N—R₁R₂R₃, wherein R₁ is C₁-C₈alkyl optionally substituted by OH or NH₂, R₂ is H or C₁-C₈ alkyloptionally substituted by OH, and R₃ is C₁-C₈ alkyl optionallysubstituted by OH. Examples of suitable amines of formula (I) includediisopropylamine, N-butyldiethanolamine,N-(3-aminopropyl)-diethanolamine, N-octylglucamine, N-ethylglucamine,N-methylglucamine, and 1-[bis(2-hydroxyethyl)amino]-2-propanol.

In some embodiments, the at least one amine can be from at least about0.001% by weight (e.g., at least about 0.002% by weight, at least about0.005% by weight, at least about 0.008% by weight, at least about 0.01%by weight, at least about 0.02% by weight, at least about 0.05% byweight, or at least about 0.1% by weight) to at most about 0.15% byweight (e.g., at most about 0.14 wt %, at most about 0.12 wt %, at mostabout 0.1 wt %, at most about 0.08 wt %, at most about 0.06 wt %, or atmost about 0.05 wt %) of the etching composition of this disclosure.Without wishing to be bound by theory, it is believed that the amine canselectively inhibit the removal of SiN, poly-Si, and SiCO when SiGe isremoved from a semiconductor substrate using the etching composition ofthis disclosure.

In general, the etching composition of this disclosure can include wateras a solvent. In some embodiments, the water can be de-ionized andultra-pure, contain no organic contaminants and have a minimumresistivity of about 4 to about 17 mega Ohms, or at least about 17 megaOhms. In some embodiments, the water is in an amount of from at leastabout 20 wt % (e.g., at least about 25% by weight, at least about 30% byweight, at least about 35% by weight, at least about 40% by weight, atleast about 45% by weight, at least about 50% by weight, at least about55% by weight, or at least about 60% by weight) to at most about 75 wt %(e.g., at most about 70 wt %, at most about 65 wt %, at most about 60 wt%, at most about 55 wt %, at most about 50 wt %, at most about 45 wt %,or at most about 40 wt %) of the etching composition. Without wishing tobe bound by theory, it is believed that, if the amount of water isgreater than 75 wt % of the composition, it would adversely impact theSiGe etch rate, and reduce its removal during the etching process. Onthe other hand, without wishing to be bound by theory, it is believedthat the etching composition of this disclosure should include a certainlevel of water (e.g., at least about 20 wt %) to keep all othercomponents solubilized and to avoid reduction in the etchingperformance.

In some embodiments, the etching composition of this disclosure canfurther include at least one (e.g., two, three, or four) organicsolvent. In some embodiments, the at least one organic solvent caninclude an alcohol or an alkylene glycol ether. Examples of suitableorganic solvents include propylene glycol, hexylene glycol,1,3-propanediol, ethylene glycol butyl ether, and3-methoxy-3-methyl-1-butanol. In some embodiments, the at least oneorganic solvent can be from at least about 10 wt % (e.g., at least about15% by weight, at least about 20% by weight, at least about 25% byweight, at least about 30% by weight, or at least about 35% by weight)to at most about 40 wt % (e.g., at most about 35 wt %, at most about 30wt %, at most about 25 wt %, at most about 20 wt %, or at most about 15wt %) of the etching composition.

In some embodiments, the etching composition of this disclosure canfurther include at least one (e.g., two, three, or four) sugar alcohol(e.g., mannitol or sorbitol). In some embodiments, the at least onesugar alcohol can be from at least about 0.001 wt % (e.g., at leastabout 0.002% by weight, at least about 0.005% by weight, at least about0.01% by weight, at least about 0.02% by weight, or at least about 0.05%by weight) to at most about 0.1 wt % (e.g., at most about 0.08 wt %, atmost about 0.06 wt %, at most about 0.05 wt %, at most about 0.04 wt %,at most about 0.02 wt %, or at most about 0.01 wt %) of the etchingcomposition. Without wishing to be bound by theory, it is believed thatincluding a sugar alcohol in the etching composition of this disclosurecan inhibit the polysilicon etch rate.

In some embodiments, the etching composition of this disclosure canfurther include at least one (e.g., two, three, or four) boronic acid.For example, the boronic acid can be of the following formula: R—B(OH)₂,in which R is C₁-C₁₀ alkyl, aryl, or heteroaryl where aryl or heteroarylcan be optionally substituted by one to six (e.g., 1, 2, 3, 4, 5, or 6)C₁-C₁₀ alkyl. Examples of suitable boronic acids include phenyl boronicacid and naphthalene-1-boronic acid.

In some embodiments, the at least one boronic acid can be from at leastabout 0.01 wt % (e.g., at least about 0.02% by weight, at least about0.05% by weight, at least about 0.1% by weight, at least about 0.2% byweight, or at least about 0.3% by weight) to at most about 0.5 wt %(e.g., at most about 0.4 wt %, at most about 0.3 wt %, at most about 0.2wt %, at most about 0.1 wt %, at most about 0.08 wt %, or at most about0.05 wt %) of the etching composition. Without wishing to be bound bytheory, it is believed that including a boronic in the etchingcomposition of this disclosure can inhibit the SiOx etch rate.

In some embodiments, the etching composition of this disclosure can havea pH of at least about 1 (e.g., at least about 1.2, at least about 1.4,at least about 1.5, at least about 1.6, at least about 1.8, at leastabout 2, at least about 2.2, at least about 2.4, or at least about 2.5)and/or at most about 3 (e.g., at most about 2.8, at most about 2.6, atmost about 2.5, at most about 2.4, at most about 2.2, at most about 2,or at most about 1.5). Without wishing to be bound by theory, it isbelieved that an etching composition having a pH higher than 3 would nothave sufficient SiGe selectivity relative to low-k dielectric materials(e.g., SiOx) as such an etching composition may have a significantlyincreased low-k dielectric material etch rate. Further, it is believedthat an etching composition having a pH lower than 1 could decomposecertain components in the composition due to strong acidity.

In addition, in some embodiments, the etching composition of the presentdisclosure may contain additives such as, pH adjusting agents, corrosioninhibitors, surfactants, additional organic solvents, biocides, anddefoaming agents as optional components. Examples of suitable additivesinclude alcohols (e.g., polyvinyl alcohol), organic acids (e.g.,iminidiacetic acid, malonic acid, oxalic acid, succinic acid, and malicacid), and inorganic acids (e.g., boric acid). Examples of suitabledefoaming agents include polysiloxane defoamers (e.g.,polydimethylsiloxane), polyethylene glycol methyl ether polymers,ethylene oxide/propylene oxide copolymers, and glycidyl ether cappedacetylenic diol ethoxylates (such as those described in U.S. Pat. No.6,717,019, herein incorporated by reference). Examples of suitablesurfactants may be cationic, anionic, nonionic or amphoteric.

In general, the etching composition of the present disclosure can have arelatively high SiGe/dielectric material (e.g., SiN, polysilicon, orSiCO) etch selectivity (i.e., a high ratio of SiGe etch rate overdielectric material etch rate). In some embodiments, the etchingcomposition can have a SiGe/dielectric material etch selectivity of atleast about 2 (e.g., at least about 3, at least about 4, at least about5, at least about 6, at least about 7, at least about 8, at least about9, at least about 10, at least about 15, at least about 20, at leastabout 30, at least about 40, or at least about 50) and/or at most about500 (e.g., at most about 100).

In some embodiments, the etching compositions of the present disclosuremay specifically exclude one or more of the additive components, in anycombination, if more than one. Such components are selected from thegroup consisting of polymers, oxygen scavengers, quaternary ammoniumsalts (including quaternary ammonium hydroxides such as TMAH), amines,alkaline bases (such as NaOH, KOH, and LiOH), surfactants other than adefoamer, a defoamer, fluoride containing compounds, abrasives,silicates, hydroxycarboxylic acids containing more than two hydroxylgroups, carboxylic and polycarboxylic acids lacking amino groups,silanes (e.g., alkoxysilanes), cyclic compounds (e.g., azoles (such asdiazoles, triazoles, or tetrazoles), triazines, and cyclic compoundscontaining at least two rings, such as substituted or unsubstitutednaphthalenes, or substituted or unsubstituted biphenylethers), bufferingagents, non-azole corrosion inhibitors, and metal salts (e.g., metalhalides).

The etching composition of this disclosure can be prepared by simplymixing the components together, or may be prepared by blending twocompositions in a kit. The first composition in the kit can be anaqueous solution of an oxidizing agent (e.g., H₂O₂). The secondcomposition in the kit can contain the remaining components of theetching composition of this disclosure at predetermined ratios in aconcentrated form such that the blending of the two compositions willyield a desired etching composition of the disclosure.

In some embodiments, the present disclosure features a method of etchinga semiconductor substrate containing at least one SiGe film. The methodcan include contacting a semiconductor substrate containing the at leastone SiGe film with an etching composition of this disclosure to removethe SiGe film. The method can further include rinsing the semiconductorsubstrate with a rinse solvent after the contacting step and/or dryingthe semiconductor substrate after the rinsing step. In some embodiments,the method does not substantially remove a metal conductor (e.g., Cu) ora dielectric material (e.g., SiN, polysilicon, or SiCO) in thesemiconductor substrate. For example, the method does not remove morethan about 5% by weight (e.g., more than about 3% by weight or more thanabout 1% by weight) of a metal conductor or a dielectric material in thesemiconductor substrate.

In some embodiments, the SiGe film in a semiconductor substrate caninclude at least about 10 wt % (e.g., at least about 12 wt %, at leastabout 14 wt %, at least about 15 wt %, at least about 16 wt %, at leastabout 18 wt %, or at least about 20 wt %) and/or at most about 35 wt %(e.g., at most about 34 wt %, at most about 32 wt %, at most about 30 wt%, at most about 28 wt %, at most about 26 wt %, at most about 25 wt %,at most about 24 wt %, at most about 22 wt %, at most about 20 wt %, atmost about 18 wt %, at most about 16 wt %, or at most about 15 wt %) Gein the SiGe film. Without wishing to be bound by theory, it is believedthat a SiGe film containing from about 10 wt % to about 35 wt % Ge canbe more easily removed from a semiconductor substrate by an etchingcomposition compared to a film containing more than 35 wt % or less than10 wt % Ge.

In some embodiments, the etching method includes the steps of:

(A) providing a semiconductor substrate containing a SiGe film;

(B) contacting the semiconductor substrate with an etching compositiondescribed herein;

(C) rinsing the semiconductor substrate with one or more suitable rinsesolvents; and

(D) optionally, drying the semiconductor substrate (e.g., by anysuitable means that removes the rinse solvent and does not compromisethe integrity of the semiconductor substrate).

The semiconductor substrates containing SiGe to be etched in this methodcan contain organic and organometallic residues, and a range of metaloxides, some or all of which may also be removed during the etchingprocess.

Semiconductor substrates described herein (e.g., wafers) typically areconstructed of silicon, silicon germanium, Group III-V compounds such asGaAs, or any combination thereof. The semiconductor substrates canadditionally contain exposed integrated circuit structures such asinterconnect features (e.g., metal lines and dielectric materials).Metals and metal alloys used for interconnect features include, but arenot limited to, aluminum, aluminum alloyed with copper, copper,titanium, tantalum, cobalt, silicon, titanium nitride, tantalum nitride,and tungsten. The semiconductor substrates may also contain layers ofinterlayer dielectrics, polysilicon, silicon oxide, silicon nitride,silicon carbide, titanium oxide, and carbon doped silicon oxides.

A semiconductor substrate can be contacted with the etching compositionby any suitable method, such as placing the etching composition into atank and immersing and/or submerging the semiconductor substrate intothe etching composition, spraying the etching composition onto thesemiconductor substrate, streaming the etching composition onto thesemiconductor substrate, or any combinations thereof.

The etching composition of the present disclosure can be effectivelyused up to a temperature of about 85° C. (e.g., from about 20° C. toabout 80° C., from about 55° C. to about 65° C., or from about 60° C. toabout 65° C.). The etch rates of SiGe increase with temperature in thisrange, thus the processes at a higher temperature can be run for shortertimes. Conversely, lower etching temperatures typically require longeretching times.

Etching times can vary over a wide range depending on the particularetching method, thickness, and temperature employed. When etching in animmersion batch type process, a suitable time range is, for example, upto about 10 minutes (e.g., from about 1 minute to about 7 minutes, fromabout 1 minute to about 5 minutes, or from about 2 minutes to about 4minutes). Etching times for a single wafer process can range from about30 seconds to about 5 minutes (e.g., from about 30 seconds to about 4minutes, from about 1 minute to about 3 minutes, or from about 1 minuteto about 2 minutes).

To further promote the etching ability of the etching composition of thepresent disclosure, mechanical agitation means can be employed. Examplesof suitable agitation means include circulation of the etchingcomposition over the substrate, streaming or spraying the etchingcomposition over the substrate, and ultrasonic or megasonic agitationduring the etching process. The orientation of the semiconductorsubstrate relative to the ground can be at any angle. Horizontal orvertical orientations are preferred.

Subsequent to the etching, the semiconductor substrate can be rinsedwith a suitable rinse solvent for about 5 seconds up to about 5 minuteswith or without agitation means. Multiple rinse steps employingdifferent rinse solvents can be employed. Examples of suitable rinsesolvents include, but are not limited to, deionized (DI) water,methanol, ethanol, isopropyl alcohol, N-methylpyrrolidinone,gamma-butyrolactone, dimethyl sulfoxide, ethyl lactate and propyleneglycol monomethyl ether acetate. Alternatively, or in addition, aqueousrinses with pH>8 (such as dilute aqueous ammonium hydroxide) can beemployed. Examples of rinse solvents include, but are not limited to,dilute aqueous ammonium hydroxide, DI water, methanol, ethanol, andisopropyl alcohol. The rinse solvent can be applied using means similarto that used in applying an etching composition described herein. Theetching composition may have been removed from the semiconductorsubstrate prior to the start of the rinsing step or it may still be incontact with the semiconductor substrate at the start of the rinsingstep. In some embodiments, the temperature employed in the rinsing stepis between 16° C. and 27° C.

Optionally, the semiconductor substrate is dried after the rinsing step.Any suitable drying means known in the art can be employed. Examples ofsuitable drying means include spin drying, flowing a dry gas across thesemiconductor substrate, or heating the semiconductor substrate with aheating means such as a hotplate or infrared lamp, Maragoni drying,rotagoni drying, IPA drying or any combinations thereof. Drying timeswill be dependent on the specific method employed but are typically onthe order of 30 seconds up to several minutes.

In some embodiments, the etching method described herein furtherincludes forming a semiconductor device (e.g., an integrated circuitdevice such as a semiconductor chip) from the semiconductor substrateobtained by the method described above.

The present disclosure is illustrated in more detail with reference tothe following examples, which are for illustrative purposes and shouldnot be construed as limiting the scope of the present disclosure.

EXAMPLES

Any percentages listed are by weight (wt %) unless otherwise specified.Controlled stirring during testing was done with a 1 inch stirring barat 300 rpm unless otherwise noted.

General Procedure 1 Formulation Blending

Samples of etching compositions were prepared by adding, while stirring,to the calculated amount of the solvent the remaining components of theformulation. After a uniform solution was achieved, optional additives,if used, were added.

General Procedure 2 Materials and Methods

Blanket film etch rate measurements on films were carried out usingcommercially available unpatterned 300 mm diameter wafers that werediced into 0.5″×1.0″ test coupons for evaluation. Primary blanket filmmaterials used for testing include 1) a SiGe film of about 500 Åthickness deposited on a silicon substrate; 2) a SiNx film of about 600Å thickness deposited on a silicon substrate, 3) a polysilicon film ofabout 1000 Å thickness deposited on a silicon substrate; 4) a SiCO filmof about 200 Å thickness deposited on a silicon substrate, and 5) a SiOxfilm of about 1200 Å thickness deposited on a silicon substrate.

The blanket film test coupons were measured for pre-treatment andpost-treatment thickness to determine blanket film etch rates. For theSiGe, SiNx, SiOx, and polysilicon blanket films, the film thicknesseswere measured pre-treatment and post-treatment by Ellipsometry using aWoollam VASE.

Patterned test coupons SiGe (3 nm)/Si were evaluated for materialscompatibility and/or etching responses. The post-treatment test couponswere then subjected to evaluation by scanning electron microscopy (SEM).The SEM images from the post treatment coupon were compared to apreviously taken pre-treatment SEM image set to evaluate materialscompatibility and etching response of each test formulation with thepatterned test device features.

General Procedure 3 Etching Evaluation with Beaker Test

All blanket film etch testing was carried out at room temperature(21-23° C.) in a 600 mL glass beaker containing 200 g of a samplesolution with continuous stirring at 250 rpm, with the Parafilm® coverin place at all times to minimize evaporative losses. All blanket testcoupons having a blanket dielectric film exposed on one side to thesample solution were diced by diamond scribe into 0.5″×1.0″ square testcoupon size for beaker scale testing. Each individual test coupon washeld into position using a single 4″ long, locking plastic tweezersclip. The test coupon, held on one edge by the locking tweezers clip,was suspended into the 600 mL HDPE beaker and immersed into the 200 gtest solution while the solution was stirred continuously at 250 rpm atroom temperature. Immediately after each sample coupon was placed intothe stirred solution, the top of the 600 mL HDPE beaker was covered andresealed with Parafilm®. The test coupons were held static in thestirred solution until the treatment time (as described in GeneralProcedure 3A) had elapsed. After the treatment time in the test solutionhad elapsed, the sample coupons were immediately removed from the 600 mLHDPE beaker and rinsed according to General Procedure 3A. After thefinal IPA rinse step, all test coupons were subject to a filterednitrogen gas blow off step using a hand held nitrogen gas blower whichforcefully removed all traces of IPA to produce a final dry sample fortest measurements.

General Procedure 3A (Blanket Test Coupons)

Immediately after a treatment time of 2 to 10 minutes according toGeneral Procedure 3, the coupon was immersed in a 300 mL volume ofultra-high purity deionized (DI) water for 15 seconds with mildagitation, which was followed by 300 mL of isopropyl alcohol (IPA) for15 seconds with mild agitation, and a final rinse in 300 mL of IPA for15 seconds with mild agitation. The processing was completed accordingto General Procedure 3.

Example 1

Formulation Examples 1-8 (FE-1 to FE-8) were prepared according toGeneral Procedure 1, and evaluated according to General Procedures 2 and3A. The formulations and the test results are summarized in Table 1.

TABLE 1 Composition [wt %] FE-1 FE-2 FE-3 FE-4 FE-5 FE-6 FE-7 FE-8Hydrofluoric acid 0.3% 0.3% 0.3% 0.3% 0.3% 0.3% 0.3% 0.3% HydrogenPeroxide 8.5% 8.5% 8.5% 8.5% 8.5% 8.5% 8.5% 8.5% Acetic acid  45%  45% 45%  45%  45%  45%  45%  45% Takesurf A-47Q 0.01%  0.01%  0.01%  0.01% 0.01%  0.01%  0.01%  0.005%  Amine 0.01% DIPA 0.01% BDEA 0.01% APDA0.01% OGA 0.01% EGA 0.01% MGA 0.01% BHEAP 0.005% APDA Water 46.18% 46.18%  46.18%  46.18%  46.18%  46.18%  46.18%  46.19%  Total 100% 100%  100%  100%  100%  100%  100%  100%  Test results SiGe25 ER (Å/min)94.7  65.7  90   N/A 60.8  62.2  58.8  100    SiNx ER (Å/min) 2.5 2.70   N/A 2.2 1.6 1.9 0.5 Poly-Si ER (Å/min) 3.0 2.9 1.4 N/A 3.0 3.0 2.82.7 SiCO ER (Å/min) 0.6 0.5 0.4 N/A 0.3 0.4 0.4 0.7 SiOx ER (Å/min) N/AN/A 34.08 104.31 N/A N/A N/A N/A DIPA = Diisopropylamine BDEA =N-butyldiethanolamine APDA = N-(3-aminopropyl)-diethanolamine OGA =N-octylglucamine EGA = N-ethylglucamine MGA = N-methylglucamine BHEAP =1-[Bis(2-hydroxyethyl)amino]-2-propanol SiGe25 = a SiGe film containing25 wt % Ge ER = etch rate N/A = Not available

As shown in Table 1, FE-1 to FE-3 and FE-5 to FE-8 (which includeTakesurf A-47Q and various amines described herein) all exhibitedrelatively high SiGe25/SiNx, SiGe25/poly-Si, and SiGe25/SiCO etchselectivity. In other words, these formulations could effectively removethe SiGe film while minimizing the removal of exposed SiNx, poly-Si, andSICO on a semiconductor substrate during the etching process. Althoughsome of these formulations exhibited relatively high SiOx etch rate, alow SiOx etch rate or a high SiGe25/SiOx etch selectivity (althoughpreferred) are only a part of the objectives of the etching formulationsof the present disclosure. The etching formulations of the presentdisclosure can still be satisfactory for their intended purposes even ifthey exhibit a relatively high SiOx etch rate.

Comparative Formulation Examples 1-5 (CFE-1 to CFE-5) were preparedaccording to General Procedure 1, and evaluated according to GeneralProcedures 2 and 3A. The formulations and the test results aresummarized in Table 2.

TABLE 2 Composition [wt %] CFE-1 CFE-2 CFE-3 CFE-4 CFE-5 CFE-6 CFE-7CFE-8 Hydrofluoric acid 0.5% 0.5% 0.3% 0.3% 0.3% 0.3% 0.3%  0% HydrogenPeroxide 8.5% 8.5% 8.5% 8.5% 8.5% 8.5% 8.5% 8.5% Acetic acid  45%  45% 45%  45%  45%  45%  45%  45% Surfactant None 0.01% 0.01% PSSA 0.01%0.01% PSSA None None None Takesurf Takesurf A-47Q A-47Q Amine None NoneNone None None None None None Additive None None None 0.005% PVP 0.005%PVP 0.002% APDA 0.01% APDA 0.3% HFA Water  46% 45.99% 46.19% 46.185% 46.185%  46.198%  46.19%  46.18%  Total 100%  100%  100%  100%  100% 100%  100%  100%  Test results SiGe25 ER (Å/min) 142.5  143.3  140.5 53.7  50.9  95.9  106.3  0   SiNx ER (Å/min) 7.4 2.5 2.5 0.8 1.6 5.4 6  0   Poly-Si ER (Å/min) N/A 5.8 5.6 2.4 2.8 4   1.4 0.1 SiCO ER (Å/min)N/A 0.3 0.4 1.1 0   0.6 0.5 0.7 SiOx ER (Å/min) N/A N/A N/A N/A N/A N/AN/A 1.5 PSSA = Poly (4-styrene sulfonic acid) PVP = PolyvinylpyrrolidoneHFA = Hexfluorosilicic acid

As shown in Table 2, CFE-1 contained no Takesurf A-47Q or amine. As aresult, it exhibited a relatively high SiNx etch rate. CFE-2 containedTakesurf A-47Q but contained no amine. The results showed that thisformulation exhibited a much lower SiNx etch rate but a relatively highpoly-Si etch rate. CFE-3 was identical to CFE-2 except that TakesurfA-47Q was replaced by another sulfonic acid. The results show again thatthis formulation exhibited a relatively high poly-Si etch rate. CFE-4contained Takesurf A-47Q, contained no amine, and contained an additive(i.e., PVP). The results showed that, although this formulationexhibited a relatively low poly-Si etch rate, its SiGe etch rate wasreduced. CFE-5 was identical to CFE-4 except that Takesurf A-47Q wasreplaced by another sulfonic acid. The results show again that thisformulation again exhibited a relatively low SiGe etch rate. CFE-6 andCFE-7 were identical to CFE-1 except that an amine of formula (I)described herein was added into these two formulations. Similar toCFE-1, the results show that these two formulations exhibited relativelyhigh SiNx etch rates. CFE-8 contained no HF, no Takesurf A-47Q, and noamine. The results showed that it did not etch SiGe at all, which is atarget material to be removed by the etching compositions described inthe present disclosure.

Example 2

Formulation Examples 9 and 10 (FE-9 and FE-10) were prepared accordingto General Procedure 1, and evaluated according to General Procedures 2and 3A. The formulations and the test results are summarized in Table 3.

TABLE 3 Composition [wt %] FE-9 FE-10 Hydrofluoric acid  0.3%  0.3%Hydrogen Peroxide  8.5%  8.5% Acetic acid  45%  45% Takesurf A-47Q 0.01%0.01% APDA 0.01% 0.01% Additive 0.01% 0.01% D-Mannitol D-Sorbitol Water46.17%  46.17%  Total  100%  100% Test results SiGe25 ER (Å/min) 96.4 97.8  SiNx ER (Å/min) 0   0   Poly-Si ER (Å/min) 1.8 1.8 SiCO ER (Å/min)0.9 0.9 SiOx ER (Å/min) 36.8  35.0 

As shown in Table 3, FE-9 and FE-10 included an additive (i.e., a sugaralcohol) in their formulations. The results show that both formulationsexhibited excellent SiGe25/SiNx, SiGe25/poly-Si, and SiGw25/SiCO etchselectivity.

Example 3

Formulation Examples 11-15 (FE-11 to FE-15) were prepared according toGeneral Procedure 1, and evaluated according to General Procedures 2 and3A. The formulations the test results are summarized in Table 4.

TABLE 4 Composition [wt %] FE-11 FE-12 FE-13 FE-14 FE-15 Hydrofluoric0.27% 0.24% 0.21% 0.18% 0.15% acid Hydrogen 7.65%  6.8% 5.95%  5.1%4.25% Peroxide Acetic acid 40.5%  36% 31.5%  27% 22.5% Takesurf 0.01%0.01% 0.01% 0.01% 0.01% A-47Q APDA 0.01% 0.01% 0.01% 0.01% 0.01% Water51.56%  56.94%  62.32%  67.7% 73.8% Total  100%  100%  100%  100%  100%Test results SiGe25 ER 115.8  103.2  82.5  68.6  48   (Å/min) SiNx ER0   0   0   0   0   (Å/min) Poly-Si ER 2.4 2.1 1.9 1.9 1.5 (Å/min) SiCOER (Å/min) 0.4 0.3 0.3 0.3 0.4 SiOx ER (Å/min) 36.58 32.97 28.8  23.3218.57

As shown in Table 4, FE-11 to FE-15 contained an increasing percentageof water and decreasing percentages of HF, H₂O₂, and HAc. These resultsshow that, as the percentage of water increased, the SiGe25 etch ratedecreased, while the SiOx etch rate also decreased. In other words,these data suggest that water can inhibit SiGe and SiOx etch ratesduring the etching process.

Example 4

Formulation Examples 16-21 (FE-16 to FE-21) were prepared according toGeneral Procedure 1, and evaluated according to General Procedures 2 and3A. The formulations and the test results are summarized in Table 5.

TABLE 5 Composition [wt %] FE-16 FE-17 FE-18 FE-19 FE-20 FE-21Hydrofluoric acid  0.3%  0.3%  0.3%  0.3%  0.3%  0.3% Hydrogen peroxide 8.5%  8.5%  8.5%  8.5%  8.5%  8.5% Acetic acid 69.91%    45%   45%  45%   45%   45% Takesurf A-47Q 0.01% 0.01% 0.01% 0.01% 0.01% 0.01%APDA 0.01% 0.01% 0.01% 0.01% 0.01% 0.01% Organic solvent None 24.91% PG24.91% HG 24.91% EGBE 24.91% MMB 24.91% PD Water 21.27%  21.27%  21.27% 21.27%  21.27%  21.27%  Total  100%  100%  100%  100%  100%  100% Testresults SiGe25 ER (Å/min) 125.3  86.0  91.9  92.1  92.6  92.1  SiNx ER(Å/min) 0   0   0   0.4 1.5 0   Poly-Si ER (Å/min) 2.3 2.4 2.7 2.9 2.02.9 SiCO ER (Å/min) 0.8 0.7 1.6 4.7  0.76 0.9 SiOx ER (Å/min) 27.8 16.1  22.7  27.7  18.6  18.0  PG = Propylene glycol HG = Hexylene glycolEGBE = Ethylene glycol butyl ether MMB = 3-Methoxy-3-methyl-1-butanol PD= 1,3-Propanediol

As shown in Table 5, FE-16 contained no organic solvent, and FE-17 toFE-21 contained different water soluble organic solvents. The resultsshowed that formulations FE-16 to FE-19 and FE-21 exhibited relativelyhigh SiGe25/SiNx, SiGe25/poly-Si, and SiGe25/SiCO etch selectivity. Therelevant data for formulation FE-20 were not measured. In addition,without wishing to be bound by theory, it is believed that propyleneglycol, hexylene glycol, 3-methoxy-3-methyl-1-butanol, and1,3-propanediol can inhibit the SiOx etch rate.

Example 5

Formulation Examples 22-31 (FE-22 to FE-31) were prepared according toGeneral Procedure 1, and evaluated according to General Procedures 2 and3A. The formulations and the test results are summarized in Table 6.

TABLE 6 Composition [wt %] FE-22 FE-23 FE-24 FE-25 FE-26 FE-27 FE-28FE-29 FE-30 FE-31 Hydrofluoric acid  0.3%  0.3%  0.3%  0.3%  0.3%  0.3% 0.3%  0.3%  0.3%  0.3% Hydrogen peroxide  8.5%  8.5%  8.5%  8.5%  8.5% 8.5%  8.5%  8.5%  8.5%  8.5% Acetic acid 69.6% 69.6% 69.6% 69.6% 69.6%69.6% 69.6% 69.6% 69.6% 69.6% Takesurf A-47Q 0.01% 0.01% 0.01% 0.01%0.01% 0.01% 0.01% 0.01% 0.01% 0.01% APDA 0.01% 0.01% 0.01% 0.01% 0.01%0.01% 0.01% 0.01% 0.01% 0.01% Additive 0.25% PVA 0.25% IA 0.25% MLA0.25% OA 0.25% SA 0.25% MA 0.25% BA 0.1% BA 0.04% BA 0.01% BA Water21.33%  21.33%  21.33%  21.33%  21.33%  21.33%  21.33%  21.48%  21.54% 21.57%  Total  100%  100%  100%  100%  100%  100%  100%  100%  100% 100% Test results SiGe25 ER (Å/min) 100.0 129.0 113.4 114.5 109.1 113.00.1 72.5 98.4 95.5 SiOx ER (Å/min)  26.0  31.7  26.5  26.9  27.0  27.20.8 18.3 26.4 24.9 PVA = Polyvinyl alcohol IA = Iminidiacetic acid MLA =Malonic acid OA = Oxalic acid SA = Succinic acid MA = Malic acid BA =Boric acid

As shown in Table 6, formulations FE-22 to FE-31 contained differentadditives. The results showed that formulations FE-22 to FE-27 and FE-29to FE-31 exhibited relatively high SiGe25 etch rates and relatively lowSiOx etch rates. In particular, the results for formulations FE-28 toFE-31 show that as the amount of boric acid increased from 0.01% to0.25%, both the SiGe25 etch rate and the SiOx etch rate decreased.Formulation FE-28 exhibited both low SiGe25 etch rate and low SiOx etchrate, which is believed to be due to the presence of a large amount(i.e., 0.25%) of boric acid.

Example 6

Formulation Examples 32-37 (FE-32 to FE-37) were prepared according toGeneral Procedure 1, and evaluated according to General Procedures 2 and3A. The formulations and the test results are summarized in Table 7.

TABLE 7 Composition [wt %] FE-32 FE-33 FE-34 FE-35 FE-36 FE-37Hydrofluoric acid  0.3%  0.3%  0.3%  0.3% 0.3% 0.2% Hydrogen peroxide 8.5%  8.5%  8.5%  8.5% 8.5% 8.5% Acetic acid 69.84%  69.84%  69.84% 69.84%   45%  45% Takesurf A-47Q 0.01% 0.01% 0.01% 0.01% 0.01%  0.01% APDA 0.01% 0.01% 0.01% 0.01% 0.01%  0.01%  Organic Solvent None NoneNone None 24.91% PG None Additive 0.05% PBA 0.1% PBA 0.05% NBA 0.1% NBA0.05% PBA 0.025% NBA Water 21.29%  21.24%  21.29%  21.24%  21.22% 46.23%  Total  100%  100%  100%  100% 100%  100%  Test results SiGe25 ER(Å/min) 124.3 106.5  145.9 142.9  91.3  93.3  SiNx ER (Å/min) N/A 0  N/A 0   0   0   Poly-Si ER (Å/min) N/A 3.0 N/A 6.9 2.7 7.1 SiCO ER(Å/min) N/A 1.0 N/A 0.7 1.0 1.0 SiOx ER (Å/min)  26.0 31.7   26.5 26.9 12.4  22.7  PBA = Phenyl boronic acid NBA = Naphthalene-1-boronic acid

As shown in Table 7, formulations FE-32 to FE-37 contained either phenylboronic acid or naphthalene-1-boronic acid as an additive. The resultsshowed that all formulations exhibited relatively high SiGe25/SiNx,SiGe25/poly-Si, and SiGe25/SiCo etch selectivity. The also exhibitedrelatively low SiOx etch rates.

Example 7

Comparative Formulation Examples 9-12 (CFE-9 to CFE-12) were preparedaccording to General Procedure 1, and evaluated according to GeneralProcedures 2 and 3A. The formulations and the test results aresummarized in Table 8.

TABLE 8 Composition [wt %] CFE-9 CFE-10 CFE-11 CFE-12 Hydrofluoric acid 0.1% 0.038% 0.05%  0.1% Hydrogen peroxide None None None None Aceticacid None None None None Nitric acid 43.08%  43.08%  43%   43% TakesurfA-47Q 0.02% None 0.02% 0.02% APDA 0.02% None 0.02% 0.02% Organic SolventNone None None 20% PG Water 56.78%  56.88% 56.91%  36.86%  Total  100% 100%  100%  100% Test results SiGe25 ER (Å/min) 64.1 54.5  115.6  30.0 SiNx ER (Å/min)  0.8 2.7 0.4 0.9 Poly-Si ER (Å/min) 11.5 3.0 5.4 1.1SiCO ER (Å/min) 0  1.5 0   0.5 SiOx ER (Å/min) 76.0 16.3  49.9  48.7 

As shown in Table 8, formulations CFE-9 to CFE-12 contained no hydrogenhydroxide and no acetic acid. The results showed that formulationsCFE-9, CFE-11, and CFE-12 exhibited relatively high SiOx etch rates.Although formulation CFE-10 exhibited relatively low SiOx etch rates, italso had relatively low etch rate for removing SiGe, a target materialto be removed by the etching compositions described in the presentdisclosure.

Example 8

Formulation Examples 38-44 (FE-38 to FE-44) were prepared according toGeneral Procedure 1, and evaluated according to General Procedures 2 and3A. The formulations and the test results are summarized in Table 9.

TABLE 9 Composition [wt %] FE-38 FE-39 FE-40 FE-41 FE-42 FE-43 FE-44Hydrofluoric acid  0.3%  0.3% 0.3%  0.3%  0.3%  0.3%  0.3% Hydrogenperoxide  8.5%  8.5% 8.5%  8.5%  8.5%  8.5%  8.5% Acetic acid 25.79% None  35% 81.15%  56.22%  56.22%  76.15%  Acetic anhydride 55.52%  55.6%36.28%  None None None None Takesurf A-47Q 0.01% 0.01% 0.01%  0.01%0.01% 0.01% 0.01% APDA 0.01% 0.01% 0.01%  0.01% 0.01% 0.01% 0.01%Organic Solvent None 25.79% PG 10% PG None 25% PG 20% PG None Water9.87% 9.79% 9.9% 10.03%  9.96% 14.96%  15.03%  Total  100%  100% 100%  100%  100%  100%  100% Test results SiGe25 ER (Å/min) 105.4  40.5 95.8  N/A 65.4 75.1 130.4 SiNx ER (Å/min) 1.7 0.5 1.3 N/A N/A N/A N/APoly-Si ER (Å/min) 3.8 1.1 3.9 N/A N/A N/A N/A SiCO ER (Å/min) 1.2 1.11.8 N/A N/A N/A N/A SiOx ER (Å/min) 13.2  4.6 10.6  N/A 11.2 15.9  23.8

Formulations FE-38, FE-40, and FE-41 contained yellow/brown precipitate,which is believed to be Takesurf A-47Q precipitated from the solutiondue to the presence of a relatively small amount of water and organicsolvent in the formulations. On the other hand, the other fourformulations did not contain any precipitate, indicating that allsolutes were dissolved in these formulations.

As shown in Table 9, all of these formulations (except for FE-42 whosedata were not measure) exhibited relatively low SiOx etch rates. Inaddition, formulations FE-38 to FE-40 exhibited relatively highSiGe/SiNx, SiGe/poly-Si, and SiGe/SiCO etch selectivity.

Example 9

Formulation Examples 45-52 (FE-45 to FE-52) were prepared according toGeneral Procedure 1, and evaluated according to General Procedures 2 and3A. The formulations and the test results are summarized in Table 10.

TABLE 10 Composition [wt %] FE-45 FE-46 FE-47 FE-48 FE-49 FE-50 FE-51FE-52 Hydrofluoric acid  0.3%  0.3%  0.3%  0.3%  0.3%  0.3%  0.3% 0.3%Hydrogen peroxide  8.5%  8.5%  8.5%  8.5%  8.5%  8.5%  8.5% 8.5% Aceticanhydride 70.06%  70.06%  70.06%  70.06%  70.06%  70.06%  65.01% 65.01%  Takesurf A-47Q 0.01% 0.01% 0.01% 0.01% 0.01% 0.01% 0.01% 0.01% APDA 0.01% 0.01% 0.01% 0.01% 0.01% 0.01% 0.01% 0.01%  Organic SolventNone None None None None None 5% MMB 5% MMB Additive 0.01% PBA 0.02% PBA0.04% PBA 0.06% PBA 0.075% PBA 0.1% PBA 0.05% PBA 0.1% PBA Water 21.11% 21.1% 21.08%  21.06%  21.045%  21.02%  21.12%  21.07%  Total  100%  100% 100%  100%  100%  100%  100% 100%  Test results SiGe25 ER (Å/min) N/AN/A N/A N/A N/A 117.2  N/A 109.9  SiGe20 ER (Å/min) 153.1 159.0 151.1147.0 145.4 154.4  139.2 124.4  SiNx ER (Å/min) N/A N/A N/A N/A N/A 3.20.8 0.6 Poly-Si ER (Å/min) N/A N/A N/A N/A N/A 4.8 N/A 5.5 SiCO ER(Å/min) N/A N/A N/A N/A N/A 1.3 N/A 0.8 SiOx ER (Å/min)  17.6  18.4 16.0  14.2  14.5 10.6   15.2 11.7  SiGe20 = a SiGe film containing 20wt % Ge

As shown in Table 10, formulations FE-45 to FE-52 contained aceticanhydride instead of acetic acid and contained phenyl boronic acid (PBA)as an additive. The results showed that all formulations exhibitedrelatively high SiGe etch rates and relatively low SiOx etch rates. Inaddition, formulations FE-50 and FE-52 exhibited relatively highSiGe/SiNx, SiGe/poly-Si, and SiGe/SiCO etch selectivity.

While the invention has been described in detail with reference tocertain embodiments thereof, it will be understood that modificationsand variations are within the spirit and scope of that which isdescribed and claimed.

What is claimed is:
 1. An etching composition, comprising: at least onefluorine-containing acid, the at least one fluorine-containing acidcomprising hydrofluoric acid or hexafluorosilicic acid; at least oneoxidizing agent; at least one organic acid or an anhydride thereof, theat least one organic acid comprising formic acid, acetic acid, propionicacid, or butyric acid; at least one polymerized naphthalene sulfonicacid; at least one amine, the at least one amine comprising an amine offormula (I): N—R₁R₂R₃, wherein R₁ is C₁-C₈ alkyl optionally substitutedby OH or NH₂, R₂ is H or C₁-C₈ alkyl optionally substituted by OH, andR₃ is C₁-C₈ alkyl optionally substituted by OH; and water; wherein thecomposition is free of a metal salt.
 2. The composition of claim 1,wherein the at least one polymerized naphthalene sulfonic acid comprisesa sulfonic acid having a structure of

in which n is 3 to
 6. 3. The composition of claim 1, wherein the atleast one polymerized naphthalene sulfonic acid is in an amount of fromabout 0.005 wt % to about 0.15 wt % of the composition.
 4. Thecomposition of claim 1, wherein the amine of formula (I) isdiisopropylamine, N-butyldiethanolamine,N-(3-aminopropyl)-diethanolamine, N-octylglucamine, N-ethylglucamine,N-methylglucamine, or 1-[bis(2-hydroxyethyl)amino]-2-propanol.
 5. Thecomposition of claim 1, wherein the at least one amine is in an amountof from about 0.001 wt % to about 0.15 wt % of the composition.
 6. Thecomposition of claim 1, wherein the at least one fluorine-containingacid is in an amount of at most about 2 wt % of the composition.
 7. Thecomposition of claim 1, wherein the at least one oxidizing agentcomprises hydrogen peroxide or peracetic acid.
 8. The composition ofclaim 1, wherein the at least one oxidizing agent is in an amount offrom about 5 wt % to about 20 wt % of the composition.
 9. Thecomposition of claim 1, wherein the at least one organic acid or ananhydride thereof comprises acetic acid or acetic anhydride.
 10. Thecomposition of claim 1, wherein the water is in an amount of from about20 wt % to about 75 wt of the composition.
 11. The composition of claim1, further comprising at least one organic solvent.
 12. The compositionof claim 11, wherein the at least one organic solvent comprises analcohol or an alkylene glycol ether.
 13. The composition of claim 11,wherein the at least one organic solvent comprises propylene glycol,hexylene glycol, 1,3-propanediol, or ethylene glycol butyl ether. 14.The composition of claim 11, wherein the at least one organic solvent isin an amount of from about 10 wt % to about 40 wt % of the composition.15. The composition of claim 1, further comprising at least one sugaralcohol.
 16. The composition of claim 15, wherein the at least one sugaralcohol comprises mannitol or sorbitol.
 17. The composition of claim 1,further comprising at least one boronic acid.
 18. The composition ofclaim 17, wherein the at least one boronic acid comprise phenyl boronicacid or naphthalene-1-boronic acid.
 19. The composition of claim 17,wherein the at least one boronic acid is in an amount of from about 0.01wt % to about 0.5 wt % of the composition.
 20. The composition of claim1, wherein the composition has a pH of 1-3.
 21. An etching composition,comprising: at least one fluorine-containing acid, the at least onefluorine-containing acid comprising hydrofluoric acid orhexafluorosilicic acid; at least one oxidizing agent; at least oneorganic acid or an anhydride thereof, the at least one organic acidcomprising formic acid, acetic acid, propionic acid, or butyric acid; atleast one polymerized naphthalene sulfonic acid; at least one amine, theat least one amine comprising an amine of formula (I): N—R₁R₂R₃, whereinR₁ is C₁-C₈ alkyl optionally substituted by OH or NH₂, R₂ is H or C₁-C₈alkyl optionally substituted by OH, and R₃ is C₁-C₈ alkyl optionallysubstituted by OH; and water; wherein the at least one organic acid oran anhydride thereof is in an amount of from about 30 wt % to about 90wt % of the composition.
 22. The composition of claim 21, wherein the atleast one organic acid or an anhydride thereof comprises acetic acid andacetic anhydride, and the total amount of the acetic acid and aceticanhydride is from about 30 wt % to about 90 wt % of the composition. 23.The composition of claim 22, wherein the total amount of the acetic acidand acetic anhydride is from about 60 wt % to about 80 wt % of thecomposition.
 24. The composition of claim 21, further comprising aninorganic acid.
 25. The composition of claim 21, wherein the compositioncomprises: at least one fluorine-containing acid, the at least onefluorine-containing acid comprising hydrofluoric acid orhexafluorosilicic acid and being in an amount of at most about 2 wt % ofthe composition; at least one oxidizing agent in an amount of from about5 wt % to about 20 wt % of the composition; at least one organic acid oran anhydride thereof, the at least one organic acid comprising formicacid, acetic acid, propionic acid, or butyric acid and being in anamount of from about 30 wt % to about 90 wt % of the composition; atleast one polymerized naphthalene sulfonic acid in an amount of fromabout 0.005 wt % to about 0.15 wt % of the composition; at least oneamine, the at least one amine comprising an amine of formula (I):N—R₁R₂R₃, wherein R₁ is C₁-C₈ alkyl optionally substituted by OH or NH₂,R₂ is H or C₁-C₈ alkyl optionally substituted by OH, and R₃ is C₁-C₈alkyl optionally substituted by OH and the at least one amine being inan amount of from about 0.001 wt % to about 0.15 wt % of thecomposition; and water.
 26. The composition of claim 25, wherein the atleast one fluorine-containing acid is at most about 0.5 wt % of thecomposition.
 27. The composition of claim 25, wherein the at least oneoxidizing agent is from about 6 wt % to about 10 wt % of thecomposition.
 28. The composition of claim 25, wherein the at least oneorganic acid or an anhydride thereof comprises acetic acid and aceticanhydride, and the total amount of the acetic acid and acetic anhydrideis from about 30 wt % to about 90 wt % of the composition.
 29. Thecomposition of claim 28, wherein the total amount of the acetic acid andacetic anhydride is from about 60 wt % to about 80 wt % of thecomposition.
 30. The composition of claim 25, wherein the at least onepolymerized naphthalene sulfonic acid is from about 0.005 wt % to about0.05 wt % of the composition.
 31. The composition of claim 25, whereinthe at least one amine is from about 0.005 wt % to about 0.05 wt % ofthe composition.
 32. The composition of claim 25, further comprising aninorganic acid.
 33. A method, comprising: contacting a semiconductorsubstrate containing a SiGe film with a composition of claim 1 tosubstantially remove the SiGe film.
 34. The method of claim 33, whereinthe SiGe film comprises from about 10 wt % to about 25 wt % Ge.
 35. Themethod of claim 33, further comprising rinsing the semiconductorsubstrate with a rinse solvent after the contacting step.
 36. The methodof claim 35, further comprising drying the semiconductor substrate afterthe rinsing step.
 37. The method of claim 33, wherein the method doesnot substantially remove SiN, poly-Si, or SiCO.
 38. An article formed bythe method of claim 33, wherein the article is a semiconductor device.39. The article of claim 38, wherein the semiconductor device is anintegrated circuit.